Lobed rotors of rotary engines



Jan. 24, 1967 L. PERAS 3,299,862

LOBED ROTORS OF ROTARY ENGINES Filed June 25, 1964 I5 Sheets-Sheet 2 IiIlllI/A' .fHt/QH 'Df L ugh; n Deva s MMMM - [Hip/ways .F. 24, 1967 ,L. PERAS 3,299,862

' LOBED ROTORS 0F ROTARY ENGINES Filed June 25, 1964 5 Sheets-Sheet 3 i i l is l L -24 2 //////////////f I if/l/ Inuaniop Lac/an aras United States Patent 3,299,862 LOBED ROTORS 0F ROTARY ENGINES Lucien Peras, Billancourt, France, assignor to Regie Nationale des Usines Renault, Billancourt, France, a French works Filed June 25, 1964, Scr. No. 377,961 Claims priority, application France, Aug. 9, 1963, 944,326, Patent 1,372,662 7 Claims. (Cl. 1238) This invention relates to improvements to lobed rotors in internally liquid-cooled rotary engines.

Such rotors usually comprise an annular double-walled peripheral portion through which a cooling fluid flows and which is joined to a cylindrical central portion by radial arms within which the fluid inflow and outflow passages are formed. This central portion may serve as a hub and be directly mounted on the crankshaft eccentric, or else may receive a fitted hub which may be in one piece or be built up from several parts.

Irrespective of whichever of these latter-mentioned dispositions is adopted, the foundry work involved in manufacturing a one-piece rotor (or annular part of the rotor when the rotor has a separate hub) raises serious difliculties since use must be made of cores which are not securely supported in the mould. As a result, rejects are numerous, thus making this method of manufacture uneconomical.

Moreover, the sand is very diflicult to extract and a certain quantity invariably remains which, on becoming subsequently detached and entrained by the cooling liquid, can cause serious incidents in service.

The present invention has for its principal object to overcome these drawbacks and accordingly relates to improvements to such rotors or rotor rings, consisting in building up the latter from a plurality of parts in such manner that none of these parts embody closed cavities but only partitions that can be obtained by means of cores which can be securely embedded and the sand of which can be completely extracted.

A further feature of the invention, concerned with the constitution of the second wall of the peripheral and radial passages consists in introducing, into the moulded part or parts forming the outer contour, leak-tight boxes or solid blocks made of cellular material.

Embodiments of the invention will now be more particularly described, 'by way of example, with reference to the accompanying drawings, in which:

FIG. 1 is a section through the line II of FIG. 2, taken perpendicularly to the axis of a rotor or rotor ring having a central welded portion;

FIG. 2 shows the same rotor in cross-section through the line IIII of FIG. 1;

FIG. 3 is a section through the line IIIIII of FIG. 4, taken perpendicularly to the axis of a rotor or rotor ring having a two-part central portion bolted together;

FIG. 4 shows the same rotor in semi-cross-section through the line IVIV of FIG. 3;

FIG. 5 shows the same rotor in semi-cross-section through the line V-V of FIG. 3;

FIG. 6 is a section through the line VI-VI of FIG. 7, taken perpendicularly to the axis of a rotor or rotor ring built up from two identical parts welded together along a plane perpendicular to the rotation axis; and

FIG. 7 shows the same rotor in cross-section through the line VII-VII of FIG. 6.

The rotors illustrated by way of example are fourlobe rotors, but it is to be understood that the invention includes in its scope all lobed rotors regardless of the number of lobes formed thereon.

Referring first to FIGS. 1 and 2, the rotor shown thereon consists of a moulded part 1 forming the outer contour 2 and the lateral faces 3 of said rotor. Internally, this part embodies peripheral ribs 4 and four radial partitions 5 and 5 which interconnect the lateral walls and the outer contour. 5 and 5 refer to an in spacer rib and an in water passage, respectively.

An examination of the drawings clearly shows that the part 1 presents no casting problems, since all it requires is a single core securely retained by the centre.

In addition, the sand extraction operation can the carried out thoroughly due to the fact that all the cavities are directly accessible.

In order to form the peripheral and radial passages through which the cooling fluid is to circulate, leak-tight boxes or blocks 6 are inserted into the part 1, their number being equal to the number of rotor lobes.

The central portion of said rotor is formed by a cylindrical part 7 which is welded at 8 and 8 to the part 1 after the boxes or blocks 6 have been placed in position.

These boxes or blocks can be fabricated in a variety of ways. If boxes are to be utilized, for instance, they may be made of thin steel or aluminum sheet, or of plastic material. If blocks are to 'be utilized, they may be cast in aluminum or be made of some convenient cellular material. The specific example shown in the drawings illustrates the use of sheet metal boxes maintained in position by their edges 6 and 6 which engage into corresponding grooves in the part 7. These boxes also bear against the ribs 4 under the urge of springs 6 buttressed against the part 7.

The cooling fluid circuit, which does not itself fall within the scope of this invention, is illustrated by arrows, the fluid inlets being at 9 and 9 and the outlets at 10 and 10 The cooling fluid is first conveyed to the summits of the two hot lobes 2 then flows through the peripheral passage 93 to the summits of the cold lobes 2 Reference is next had to FIGURES 3, 4 and 5 for an alternative embodiment which differs in the following respects:

(a) Instead of being in one piece, the central portion is made up of two parts 17 and 17 which are symmetrical with respect to the transverse centerplane.

(b) Each of these parts has formed thereon a flange 17 fitting into a matching recess in the part 11 which forms the outer contour 12 and the lateral faces 13 and inside which are provided peripheral ribs 14 and radial partitions 15 15 (c) the two parts 17 and 17 are assembled together by means of bolts 18, and the action of bringing them together rigidly unites them with the part 11 and also enables the boxes 16 to be secured by a clamping onto lugs 16 thereof, as is clearly shown in FIG. 4.

(d) The means used to assemble the parts 17 and 17 to the part 11 are supplemented by cotters 18 (see FIG. 5).

(e) The cooling fluid reaches 19 at the base of the hot lobes 12 cools the latter as it flows through the peripheral passage, and then cools the cooler lobes 12 before emerging through 20 It goes without saying that this specific arrangement of the cooling circuit may also be applied to the case of the rotor. shown in FIGS. 1 and 2, and vice versa. It will suflice to that end to accordingly dispose the partitions 5 and 5 and to adapt the shape of the boxes or blocks 6 to the disposition of these partitions.

FIGS. 6 and 7 show a third embodiment of the invention.

The main portion of the rotor 21 is split into two parts along a plane which is the transverse centerplane of the rotor.

Each of the parts 21 and 21 jointly constituting the 3 rotor forms an outer half-contour 22 (or 22 the halfhub 27 (or 27 and one of the lateral faces 23 (or 23 of said rotor. Inside each of these'parts are formed pe ripheral ribs 24 and radial semi-partitions 25 and 25 After the boxes of blocks 26 have been positioned,the two parts 21 and 21 are welded together at 28 along a closed line which hugs the contour of the rotor. The assembly of the two parts 21 and 21 is consolidated by studs 31 which join together the two half-hubs 27 and 27 Y A sealing welding or brazing operation rnay be executed if required at 32 along the outer perimeter of the hub, at the joint of the two parts 21 and 21 The partitions 25 and 25 'are here shown as being in a position identical to that of FIG. 3 but, as already indicated, they could alternatively be arranged so as to extend to the summits of the lobes, as shown in FIG. 1.

I claim:

1. A lo-bed rotor for rotary engines having internal liquid cooling, said rotor comprising an annular shaped housing having an outer peripheral wall, a pair of lateral faces and a central annular open portion; a hub disposed in said open portion, and secured in said housing; a plurality of partition members disposed in said housing, extending radially outward from said hub and defining a plurality of open cavities; and a plurality of leak tight box members disposed in spaced relation relative to the cavity surfaces, the outer surfaces of said box members cooperating with said partition memebers and said wall to define a plurality of radial and peripheral cooling passages.

2. The rotor of claim 1 further comprising a plurality of ribs formed on the inner portion of said wall.

, 3. The rotor of claim 2 further comprising means disposed between said hub and said box members for urging said .box members into pressure contact with said ribs.

4. The rotor of claim 1 further comprising a pair of flanges extending outwardly from each of said box members which engage in corresponding grooves in said hub to secure said box member in said housing.

-5. The rotor of claim 1 wherein said hub comprises two, parts, said parts having a flange formed thereon which enrotor axis of rotation and at least one bolt joining said parts said parts having a flange formed thereon which engages in a recess formed in a corresponding lateral face.

6. The rotor of claim 5 wherein said box members are provided with flanges which are'clamped between the two parts of said hub.

7. The rotor of claim 1 wherein said housing, hubs and, partition members each comprise two parts connected together along a plane perpendicular to the rotor axis of rotation.

References Cited by the Examiner UNITED STATES PATENTS 3,091,386 5/1963 Paschke. 3,098,605 7/1963 Bentele et al. 3,131,679 5/1964 Peras 1238 3,176,915 4/1965 Bentele et al.

MARK NEWMAN, Primary Examiner.

F. T. SADLER, Assistant Examiner. 

1. A LOBED ROTOR FOR ROTARY ENGINE HAVING INTERNAL LIQUID COOLING, SAID ROTOR COMPRISING AN ANNULAR SHAPED HOUSING HAVING AN OUTER PERIPHERAL WALL, A PAIR OF LATERAL FACES AND A CENTRAL ANNULAR OPEN PORTION; A HUB DISPOSED IN SAID OPEN PORTION, AND SECURED IN SAID HOUSING; A PLURALITY OF PARTITION MEMBERS DISPOSED IN SAID HOUSING, EXTENDING RADIALLY OUTWARD FROM SAID HUB AND DEFINING A PLURALITY OF OPEN CAVITIES; AND A PLURALITY OF LEAK TIGHT BOX MEMBERS DISPOSED IN SPACED RELATION RELATIVE TO THE CAVITY SURFACES, THE OUTER SURFACES OF SAID BOX MEMBERS COOPERATING WITH SAID PARTITION MEMBERS AND SAID WALL TO DEFINE A PLURALITY OF RADIAL AND PERIPHERAL COOLING PASSAGES. 